Dust Control Handbook for Industrial Minerals Mining and Processing
Total Page：16
File Type：pdf, Size：1020Kb
RI 9689 REPORT OF INVESTIGATIONS/2012 Report of Investigations 9689 Dust Control Handbook for Industrial Minerals Mining and Processing Andrew B. Cecala, Andrew D. O’Brien, Joseph Schall, Jay F. Colinet, William R. Fox, Robert J. Franta, Jerry Joy, Wm. Randolph Reed, Patrick W. Reeser, John R. Rounds, Mark J. Schultz DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Institute for Occupational Safety and Health Office of Mine Safety and Health Research Pittsburgh, PA • Spokane, WA January 20122 This document is in the public domain and may be freely copied or reprinted. Disclaimer Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety and Health (NIOSH). In addition, citations to Web sites external to NIOSH do not constitute NIOSH endorsement of the sponsoring organizations or their programs or products. Furthermore, NIOSH is not responsible for the content of these Web sites. All Web addresses referenced in this document were accessible as of the publication date. Ordering Information To receive documents or other information about occupational safety and health topics, contact NIOSH at Telephone: 1–800–CDC–INFO (1–800–232–4636) TTY: 1–888–232–6348 e-mail: [email protected] or visit the NIOSH Web site at www.cdc.gov/niosh. For a monthly update on news at NIOSH, subscribe to NIOSH eNews by visiting www.cdc.gov/niosh/eNews. DHHS (NIOSH) Publication No. 2012–112 January 2012 SAFER • HEALTHIER • PEOPLE™ ii FUNDAMENTALS OF DUST COLLECTION SYSTEMS WET SPRAY SYSTEMS DRILLING AND BLASTING CRUSHING, MILLING, AND SCREENING CONVEYING AND TRANSPORT ONTENTS BAGGING BULK LOADING CONTROLS FOR SECONDARY SOURCES OPERATOR BOOTHS, CONTROL CHAPTER C ROOMS, AND ENCLOSED CABS HAUL ROADS, STOCKPILES, AND OPEN AREASiii TABLE OF CONTENTS ACRONYMS AND ABBREVIATIONS USED IN THIS HANDBOOK ....................................... xxiii UNIT OF MEASURE ABBREVIATIONS USED IN THIS HANDBOOK .................................. xxiv ACKNOWLEDGMENTS ............................................................................................................. xxv ABOUT THIS HANDBOOK ...................................................................................................... xxvi TASK FORCE COMMITTEE COCHAIRS............................................................................... xxvi TASK FORCE COMMITTEE MEMBERS ............................................................................... xxvi EDITOR ................................................................................................................................. xxvii HANDBOOK LAYOUT COORDINATOR ............................................................................. xxvii IMA-NA COORDINATOR ..................................................................................................... xxvii INTRODUCTION ........................................................................................................................... 1 SILICA EXPOSURE AND POTENTIAL HEALTH IMPACTS ...................................................... 2 REFERENCES ............................................................................................................................. 4 CHAPTER 1: FUNDAMENTALS OF DUST COLLECTION SYSTEMS ...................................... 7 BASICS OF DUST COLLECTOR SYSTEMS ............................................................................... 8 AIRFLOW AND DUST CONTROL .............................................................................................. 9 EXHAUST SYSTEMS DESIGN ................................................................................................. 11 HOODS ..................................................................................................................................... 11 Hoods and Blowing versus Exhausting Ventilation ........................................................................... 11 Hood Types .............................................................................................................................. 12 Hood Design ............................................................................................................................. 14 Air Induction ........................................................................................................................ 15 Capture Velocity .................................................................................................................... 16 Other Hood Considerations .......................................................................................................... 18 Checklist for Hood Effectiveness .................................................................................................. 19 DUCTWORK AND AIR VELOCITIES ....................................................................................... 19 High-Velocity Systems ............................................................................................................... 20 Low-Velocity Systems ................................................................................................................ 21 Airflow Target of 1,800 fpm .................................................................................................... 23 Avoidance of Horizontal Ductwork ........................................................................................... 23 The Use of Main Duct Trunk Lines ........................................................................................... 24 v Minimizing Field Fits and Welds .............................................................................................. 24 Avoiding Mitered Elbows Greater Than 90 Degrees ..................................................................... 25 Sizing and Locating Orifice Plates ............................................................................................. 25 Minimizing the Use of Flexible Hoses ....................................................................................... 26 Modified Low-Velocity (MLV) System ......................................................................................... 26 AIR CLEANING DEVICES ........................................................................................................ 28 Gravity Separators (Drop-Out Boxes) ............................................................................................ 28 Centrifugal Collectors or Cyclones ................................................................................................ 29 Baghouse Collectors ................................................................................................................... 31 Mechanical Shaker Collectors .................................................................................................. 34 Reverse Air Collectors ............................................................................................................ 36 Reverse Jet (Pulse Jet) Collectors .............................................................................................. 37 Cartridge Collectors ............................................................................................................... 38 Wet Scrubbers ........................................................................................................................... 40 Venturi Scrubbers .................................................................................................................. 41 Impingement Plate Scrubbers ................................................................................................... 41 Spray Tower Scrubbers ........................................................................................................... 42 Wet Cyclone Scrubbers ........................................................................................................... 42 Electrostatic Precipitators (ESPs) .................................................................................................. 42 COLLECTOR DISCHARGE DEVICES ...................................................................................... 43 Rotary Airlock Valves ................................................................................................................ 43 Double Dump Valves ................................................................................................................. 43 Tilt Valves ................................................................................................................................ 44 Vacuum or Dribble Valves........................................................................................................... 44 FILTER FABRICS ..................................................................................................................... 44 Particulate Collection of Fabrics ................................................................................................... 46 DESIGNING MINE/PLANT DUST COLLECTION SYSTEMS ................................................... 48 Clay Application ........................................................................................................................ 49 FANS ......................................................................................................................................... 50 Fan Operating Characteristics ....................................................................................................... 50